Rotor head dampening was too hard by stock dampers so I have changed the plastic for o-rings, the softer ones even softer than ALIGN gray solution. I bought them localy from company producing them http://www.altes.si/o-ringi.html . On the picture are dimensions 7x3mm are the right ones for Trex600 main rotor head.

So that is information about majority of mechanical upgrades. I do plan to use a scale main rotor head, but regarding that I still need to decide on solution. I will use one or two entire posts just regarding that part,....